Japanese Defense Minister Gen Nakatani indicated that Japan could conduct military operations in North Korea without consent from Seoul in the event of another war on the Korean Peninsula.

His remarks imply that Japan has set up a contingency plan to send its Self-Defense Forces (SDF) into North Korea without seeking consent from the South. He made the comments during talks with South Korean Defense Minister Han Min-koo in Seoul, Tuesday.

This clearly shows that there is a wide gap between Seoul and Tokyo about the scope of South Korean territory, adding fuel to controversy over Japan's move to expand its military role by revising the country's Constitution.

The possible landing of Japan's SDF into North Korea could become a new seed of conflict in the Northeast Asian region because Japan's military operations there could provoke China and Russia, which border the North.

According to the Ministry of National Defense, Han told Nakatani that Tokyo must seek approval or consent from Seoul first for any military activities on or near South Korean territory, which also includes North Korea according to the Constitution of the Republic of Korea.

Nakatani responded: "There have been some opinions that the valid scope of Republic of Korea's governing area is south of the Military Demarcation Line (MDL)."

The remark was construed as Japan expressing its position that it does not need to gain agreement before conducting military activities on the North Korean region.

Whether or not the SDF could enter the North without consent from Seoul has been a subject of controversy since Japan's Diet recently passed a set of controversial security bills.

The laws allow its armed forces to assist other countries in armed conflict in the name of the right to collective self-defense — the use of force to support an ally under attack.

The government has maintained that Seoul's consent is essential before the SDF enters the North, but Tokyo and Washington have not clearly expressed their positions.

During Tuesday's meeting, Nakatani told Han that Japan will seek approval from countries in accordance with international law before sending its forces into their territories.

The remark also showed differences between the two countries about whether North Korea should be included in South Korean territory, because unlike South Korea's Constitution, international law views the two Koreas as separate nations.

Nakatani said a trilateral discussion including the U.S. will be necessary.

A ministry official said, "We agree with Japan about the need for the trilateral discussion."

However, concerns are raised about whether Seoul will be able to properly deliver its position if Japan and the U.S. hold similar positions.

According to the ministry, working-level officials from the three countries will hold a meeting for two days from today in Tokyo to discuss their "mutual security concerns."

The bilateral meeting between the defense chiefs came as Tokyo has constantly expressed its hope to explain its security laws to Seoul.

In explaining why the ministry did not disclose Nakatani's core remark, which indicates that Japan perceives only south of the MDL as the Republic of Korea, right after the talks, the official said that the two countries agreed not to disclose such remarks to the media.

But the Japanese media already reported the remarks Tuesday. Some critics said that Seoul's ministry appears to be not sufficiently respected by its Japanese counterpart.